My method, for years, has been to import photos into a folder on Lightroom for editing. After removing the rejects from that folder and the hard drive, I rename and add keywords to the good ones. I move those good ones to other folders. That import folder is empty in LIghtroom, but the same folder on the hard drive and backup drives has photos in it that I have imported. Some of these photos are renamed and reside in other Lightroom folders as they should be. Some are nowhere in the Lightroom Library--not in any folder. Most of these photos are jpegs, some are CR2.

As an experiment, I moved a couple of the photos from the hard drive folder to the desktop to re-import them into Lightroom. Lightroom did not recognize them or show them to exist. I opened those photos in Photoshop and saved them as a copy. Lightroom still did not recognize them.

How can I have Lightroom recognize these photos and make the folders consistent?

When LR does not match your operating system folders, this means that either:

The photos have not been imported into LR; OR

The photos have been imported into LR accidentally using the COPY option instead of the ADD option, and so Lightroom thinks the photos are in a different folder and so the default is that you can't import them again

If situation 2 is the correct situation on your computer, you need to find the photos inside of LR. Here are the steps. Please follow all four of these steps, in order, skipping nothing

1. In the Lightroom Library Module, on the left, under Catalog, click on All Photographs

2. Turn off all filters (Ctrl-L once or twice)

3. Turn off all stacking (Photo->Stacking->Expand All Stacks)

4. Search for at least one of these photos by file name using the Lightroom Filter Bar

Thank you for your guidance. You got me started and I found my way. I always use the MOVE option, but I followed situation 2 and found a photo. The 129 photos in the folder on the hard drive, but not in the same folder in Lightroom, were of four types:

One, the photo had been imported, renamed, and moved to another folder.

Two, the photo had been imported and moved to another folder, but not renamed.

Three, the photo had been, I thought, rejected and removed from the disc.

Four, the photo had not been imported.

By scrutinizing each photo, I was able to determine the type and act accordingly. It took a while.

I should also say that I have used the same methods of importing, key-wording, and filing for 4 years. The library has 3500 photos. I must have imported near 10 times that many, for I cull and delete with vigor. I have no idea why those 129 photos were miss-filed. There seem to have been four different reasons that photos were miss-filed. All the photos seem to be from the last year or so. I guess the lesson is to check the images in the hard drive folders occasionally.